When I did the PCIe ground isolation with the Silverstone Card, and because I was able to do it sequentially (i.e. a little bit at a time) what I noticed was that as the PCIe ground become "more" isolated that external RFI/EMI influenced the USB error rates more and more up to the point that turning on or off a flourescent light anywhere in the house would cause the USB connection to be totally severed and a restart required to get it back again.

What I "think" was happening is that the induced voltage in the PC from the EMI/RFI was enough to float the voltage difference across the PCIe connection enough so that connection was no longer possible...i.e. the potential across the signal wires became too much and because there was no mecchanism to keep them the same relative to each other that a longer current loop through the main power lines had to be forced which was not able to work in this situation.

I think it is the same sort of thing that happens when we isolate the PC via the Intona/Phisolator and ethernet cable...the boxes manage to "float" relative to each other and the connection becomes unviable.  Peter, one idea that I have had about going forward with this (assuming the actual problem/s is/are correctly identified) is to get the connection working properly with a completely disconnected PC.  If you can get things working well when there is no back-door (the PE-neutral route) by battery powering the PC (temporarily, not permanently) then by my thinking it should work once the backdoor is put back in the system and the PC is plugged into the mains.  Will a completely isolated PC even be able to reliably send USB data to a dac?  That is my question!

Peter, I've enjoyed reading these posts and must say that what you are experiencing is something that I have wondered might be possible to happen (your USB troubles - especially those with the Terradak) ever since I played around with lifting the PCIe ground with the Silverstone card and just how unstable USB became.  My efforts were slightly different to your issue of course, but I have been considering lately reattaching the NOS1a to PE simply from a safety perspective, and also because it is DC coupled to a valve amp that potentially could send high voltage DC back into the NOS1a if ever something went catastrophically wrong with the amp.  Plus, I wonder how a signal can be transferred between the PC and NOS1a without the potential between the boxes being equalised, or should I say without one box floating at a different potential to the other (think USB isolation combined with ethernet isolation).

The thing that puzzles me though, is how PE and signal ground are connected and why the Phisolator seems like a player in connecting the two.  PE and mains neutral are connected together at the mains entry box (to the house) in Australia, and I assume they are similarly connected in your part of the world as well...is the Phisolator by effectively severing a potential current loop via USB cable forcing a current loop between the PC and NOS1a via the mains electricity active and neutral wires all the way back to where power comes into the house (i.e. where PE and neutral are connected)?  I hope this question makes sense. 

Would a chassis to chassis ground wire between the Stealth PC and the NOS1a help?  For current to flow there must be a voltage difference between the two boxes, so perhaps a wire between them may help.

Or perhaps I have misread the situation.

Regards,

Anthony

The intermittent ticks would give me the irrits though...it's not vinyl after all.  I get a tick at the moment when the cover art shows and that is annoying, plus I have a 5m USB cable from the Intona to the NOS1a and that gives me a few ticks every now and then and that annoys me too.

I sound so annoyed, yet I have had a very good day (I'm not really annoyed)!

Interesting Peter, have you tried Intona + Phisolator as a comparison?  Many of us already have the Intona although I do very much like the elegance of keeping everything inside the NOS1a case.

Yes, of course, I should have known.  I checked the tidal app and only the redbook version of "The Division Bell" is available.  I downloaded "Killing me Softly" as a master and played that today.  Nice.

That would be pretty cool.  I have a good FM tuner also (TU-X1) but Australia is not getting rid of FM anytime soon...thankfully.

Hi Peter,

If I type in either of those searches just the single album appears which is the Redbook version.  No remaster and no MQA it seems.

Regards,

Anthony

Hi Peter,

Probably a stupid question, but I do not see any MQA results for "The Division Bell" when I search Tidal on XXHE 2.07-05.  Should I?  Or is this something that only you can do with your beta XXHE?

Regards,

Anthony

Guys, don't be too quick to instantly dismiss Floyd Tooles works.  Without his decades of research and constant access to R&D funds to set up and perform literally thousands of blind tests in pretty much the same controlled environment I think that speaker design would still be in the dark ages...hit and miss. 

As a result of his work we know that controlled directivity and even power response are THE basic things that make or break how a speaker sounds.  His work also tells us what "most" people like to hear, and that is a diffuse sound field (i.e. lots of room reflections) with the reflections being the same frequency spectrum as the direct sound, which is where controlled directivity and power response come in i.e. a speaker sounds exactly the same on and off axis.

Of course one test setup cannot test every variant of speaker design out there, but I really do think that his basic results are indisputable.  It does not mean that he has tested everything that influences sound quality, but he does know the easy way to make a speaker sound "better", and that is the radiation pattern of its sound field.

The Orelo MKII does not have the ideal radiation pattern that Toole promotes because it uses a tractrix horn expansion (not conical or OSWG) but it is a point source and it does control the directivity of the sound above the room frequency.  Funny thing is that most of those that actually "listen" to horns prefer the tractrix expansion to those couple of expansions that are more technically correct.

As for the power response, I have no idea how the Orelo MKII fares, that stuff is difficult to measure so very few actually do it unless you have a facility just for that purpose.

Peter,

To date I have been a bit "meh" about the MQA stuff in general, but if you are suddenly excited by the possibilities then I will be as well. 

If the result is access to "the best masters" of the recordings plus with XXHE we will end up with a mix of fabulous time and frequency domain then that does sound very nice to me.

Cheers,

Anthony

Hi Peter,

I have had a chance now to further look at this Tidal login problem.  Please see the attached LOG file.

Note that I have first upgraded to XXHE 2.07 but the problem persists.

Regards,

Anthony

Thanks for clarifying the link.

That bit of your quote I have put in bold I strongly disagree with...I do not think that dynamics or lack thereof are a particular characteristic of either topology (SE or PP)...it all comes down to implementation...but doesn't everything?

Thanks VJ

Mani, here is a link to the Nelson Pass stuff you mentioned in your first post.  At least I think it is that to which you were referring.

vrao, as the resident expert, what do you make of Mr Pass' writing?  I would like to agree with him because I have skin in the game (am current building my SET amplifiers), but I have never heard anything as "real" as SET amps matched to appropriate speakers.

Yes, it is a horn.  The backchamber adds compression to the woofer as does a horn throat smaller than the size of the woofer cone.  The height  that the downfiring horn is set above the floor dictates the horn mouth area into the room.  I assume the height from the floor can be adjusted.